Missed the point
The reason this doesn’t work is because they messed up the concept and the moral of the story. They should have cast an unattractive actress to play the unattractive "test subject” and somehow made her seem more attractive in other ways which makes the other lead fall for her. They connect in ways besides physical or lust during the film.
Instead, they cast a hot actress to play an attractive characters who doesn’t know or care if she’s attractive. Then all they did was reveal that she had huge boobs and suddenly the other characters started drooling over her. It's pointless.
What's the moral? "If you're hot, go ahead and show it and you'll find love. But if you're not, you're just out of luck"?